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Takeuchi, Tomoaki; Otsuka, Noriaki; Nakano, Hiroko; Iida, Tatsuya*; Ozawa, Osamu*; Shibagaki, Taro*; Komanome, Hirohisa*; Tsuchiya, Kunihiko
QST-M-16; QST Takasaki Annual Report 2017, P. 67, 2019/03
no abstracts in English
Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11
no abstracts in English
Takeuchi, Tomoaki; Shibata, Hiroshi; Hanakawa, Hiroki; Uehara, Toshiaki*; Ueno, Shunji*; Tsuchiya, Kunihiko; Kumahara, Hajime*; Shibagaki, Taro*; Komanome, Hirohisa*
JAEA-Technology 2017-026, 26 Pages, 2018/02
JAEA-Technology-2017-026.pdf:4.0MB
Under severe accidents, high-integrity transmission techniques are necessary so as to monitor the situation of the nuclear power plant. In this study, effects of gamma irradiation up to 10
Gy on properties of optical devices were evaluated toward the development of a radiation-resistant in-water wireless transmission system using visible light. After the irradiation, for the LEDs, the total luminous flux decreased and the browning of resin lenses occurred. Meanwhile, the current-voltage characteristics hardly changed. For the PDs, the light sensitivity decreased and the browning of resin window occurred. The dark currents of PDs did not become large enough to adversely affect transmission. These results indicated that both the decreases of the total luminous flux of the LEDs and the light sensitivity of the PDs were mainly caused by not the degradation of the semiconductor parts but the browning of the resin parts by the irradiation. In addition, basic decrease behaviors of light transmission of several different types of glasses by gamma irradiation were also obtained so as to select the suitable optical windows and filters for the developing radiation-resistant in-water wireless transmission system.
Yatsuzuka, Junji*; Shibagaki, Taro*; Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Komanome, Hirohisa*
Bijon Gijutsu No Jitsuriyo Wakushoppu (ViEW 2017) Koen Yoshishu (USB Flash Drive), 6 Pages, 2017/12
no abstracts in English
Takeuchi, Tomoaki; Shibata, Hiroshi; Otsuka, Noriaki; Uehara, Toshiaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
IEEE Transactions on Nuclear Science, 63(5), p.2698 - 2702, 2016/10
Times Cited Count：3 Percentile：26.09(Engineering, Electrical & Electronic)In response to the lesson of the accident at the Fukushima Dai-ichi Nuclear Power Plant, we started a development of a radiation-resistant in-water wireless transmission system. In this study, capability of light emitting diodes (LED) and photo diodes (PD) as light emitting and receiving devices was researched. Results of irradiation tests of LEDs and PDs up to 1 MGy indicated a main cause of the degradation of the optical performances of the diodes was not the radiation damage at the semiconductor parts but the coloring of the resin parts. Assuming that the use of the candidate LED and PD, the PD's output current generated by the emission light of the LED at five meters away in water was estimated to be detectable intensity even considering the effects of the absorption of the light by water and the increased dark current by 1 MGy irradiation. Therefore, a radiation resistant in-water transmission system can be constructed using LEDs and PDs in principle.
Takeuchi, Tomoaki; Otsuka, Noriaki; Shibagaki, Taro*; Komanome, Hirohisa*; Ueno, Shunji*; Tsuchiya, Kunihiko
Nihon Hozen Gakkai Dai-13-Kai Gakujutsu Koenkai Yoshishu, p.379 - 386, 2016/07
no abstracts in English
Otsuka, Noriaki; Takeuchi, Tomoaki; Shibagaki, Taro*; Komanome, Hiroshi*; Tsuchiya, Kunihiko
Proceedings of Decommissioning and Remote Systems 2016 (D&RS 2016) (CD-ROM), p.277 - 278, 2016/07
no abstracts in English
Takeuchi, Tomoaki; Sawa, Takao*; Shibagaki, Taro*; Kozawa, Yusuke*; Goto, Shimpei*
no journal, ,
no abstracts in English
Takeuchi, Tomoaki; Shibata, Hiroshi; Ueno, Shunji; Uehara, Toshiaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
no journal, ,
no abstracts in English
Takeuchi, Tomoaki; Otsuka, Noriaki; Nakano, Hiroko; Shibagaki, Taro*; Komanome, Hirohisa*; Tsuchiya, Kunihiko
no journal, ,
Considering that reactor buildings could be filled with water under severe accidents, a development of the wireless transmission system in water is necessary. In this study, transmission method using visible light was adopted because of its relatively lower attenuation rate and higher transmission rate in water. In the designed transmission system, two-dimensional transmission devices were adopted. LEDs arranged in a two-dimensional array and a camera using a CMOS image sensor, that is like a 2D aggregation of PDs, were used as the light emission and receiving devices, respectively. Moreover, both of pattern and flicker signals can be simultaneously emitted. To confirm the environmental robustness, the in-water transmission tests using the two-dimensional transmission devices were performed with and without air bubbles. The results indicated the pattern signals were more easily influenced than the flicker signals by the air bubbles. In addition, surface mounting LEDs were more suitable than bullet-type LEDs because of their good distinctiveness of the light spots from each LED. On the other hand, 
irradiation tests for the LEDs were performed. The results again indicated surface mounting LEDs were advantageous because the decrease rates of the total luminous flux with absorbed dose were lower than that of the bullet-type LEDs.
-ray conditionOtsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
no journal, ,
no abstracts in English
Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
no journal, ,
no abstracts in English
Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*
no journal, ,
no abstracts in English
-ray degradation of light emitting and receiving devices for in-water wireless transmission systemShibata, Hiroshi; Hanakawa, Hiroki; Takeuchi, Tomoaki; Ueno, Shunji; Uehara, Toshiaki; Tsuchiya, Kunihiko; Araki, Masanori; Shibagaki, Taro*; Komanome, Hirohisa*
no journal, ,
no abstracts in English
